Usain Bolt’s Olympic gold shows again why no Asian, white–or East African–will ever be crowned world’s fastest humanRazib at the Unz Review responds:
Actually, I think Jon is wrong on this. Better drugs and biological engineering mean that I suspect at some point in the near future the fastest “human” alive is going to be non-African, and, if I had to bet, Chinese. But you know what Jon meant.Khan goes on to argue:
One peculiar thing population genetics teaches us that non-adaptive traits are more heritable. This is due to the fact that selection tends to remove variation, selecting for fitter individuals. Humans are good runners, there are entire evolutionary theories based around our biomechanical modifications and adaptations. But there’s really no benefit in running in bursts of 10.5 in the 100 meter dash vs. 9.5. We’re not that sort of ambush predator. There’s probably some heritable variation in burst ability, but it’s small, and not visible in any normal set of tasks among large groups of humans.I wouldn’t be surprised if the ability to outrun those who are after you and mean to do you harm were an important life skill that is highly adaptive in Darwinian terms.
But modern competitive sports at the Olympic level is not selecting for normality, it’s selecting from outliers. It isn’t that West Africans were guaranteed to be the best sprinters, it’s just that a priori it shouldn’t be surprising that in such a non-adaptively beneficial trait as running a few seconds faster in the 100 meter dash some populations had the genetic die loaded in their direction.
For example, in 1982, when I had just moved to Chicago, I was headed into the Century Mall on N. Clark St., when a black teen rushed out, followed by two twenty-something Hispanic security guards in close pursuit. I watched them head up Clark Street with the teen in sneakers pulling away from the guards in shiny black leather shoes.
But whether sprinting ability or distance running ability is best for survival depends upon how long pursuers’ sightlines extend in your home terrain.
The shoplifter then turned left at the first corner. It occurred to me that was an important life decision he had just made: if it was a dead end he was in big trouble. But if it were a thru street then he just needed to make a series of seemingly random turns until he had lost his pursuers.
In contrast, if the pursued had headed into open grassland, his pursuers could keep him in sight for a long time, so his better sprinting ability might prove nugatory if they had more endurance.
Perhaps in forested or brush covered terrain, as in West Africa, sprinting is selected for because the pursued individual can get lost faster, while in open grassland, as in East Africa, endurance running is the surest way to get away.